1. Field of the Invention
The present invention relates to devices for synthesizing musical tones, and more particularly, to devices which are capable of synthesizing highly complex musical tones.
2. Prior Art
Devices are conventionally known which synthesize the sound of conventional non-electronic musical instruments by electronically simulating the mechanism of sound generation thereof.
Examples of such include devices which simulate the mechanism of sound generation in wind instruments, and thereby synthesize musical tones which simulate the sound of the target wind instrument. In the case of an actual wind instrument, blowing pressurized air from a performer's mouth causes a reed component of the instrument to vibrate in a non-linear manner. This non-linear vibration of the reed acts to create vibrating air pressure waves which propagate within the hollow tubular portion of the wind instrument. The vibrating air pressure waves propagating within the wind instrument in turn interact with the vibrating reed and establish a state of resonance therewith.
With conventional devices which simulate the mechanism of sound generation in wind instruments, typically, a non-linear amplifying element is used to simulate the function of the reed in the target instrument, and a bi-directional transfer circuit simulates the propagation of air pressure waves in the hollow tubular portion of the instrument. One example of this type of conventional musical tone synthesizing device has been disclosed in Japanese Patent Application First Publication, Serial No. Sho-63-40199.
Conventional devices of the type described above, however, have limitations in terms of the fidelity with which they are able to simulate the sound of the target instrument. This problem is particularly troublesome when it is desired to simulate the sound of a wind instrument having a very complicated acoustical output. As an example, closed type networks consisting of a lossless digital waveguide which are often employed in this type of conventional synthesizing device to simulate propagating air pressure waves are frequently not capable of simulating the complex interaction of the propagating air pressure waves in certain types of wind instruments, and therefore, these devices are not able to faithfully simulate the sound of such wind instruments. Moreover, there is an increasing demand for tone synthesizing devices used in electronic musical instruments which can simulate conventional non-electronic musical instruments with very high fidelity.
On the other hand, devices of the type described above are also being developed in a different prior art entitled "Musical tone signal formation device" (U.S. Pat. No. 4,297,933). This prior art addresses the selection of tone quality by utilizing a digital FM formula which generates musical tone signals in accordance with the different algorithms (computational means). However, although this prior art utilizes an FM formula, it is not able to carry out the synthesis of complex musical tones.